What is the requirement??
Monitoring, I found that be one of the most common requirement when someone wants to do Desktop based monitoring for the agents in a Contact Center environment and require Daisy Chain for this purpose so that RTP packets can be forwarded from the phone to the client i.e. CAD/CTIOS etc.
All the phones mentioned in the Cisco Unified IP Phones for Desktop / Endpoint Monitoring section of below document can serve this purpose and can be Daisy Chained
http://docwiki.cisco.com/wiki/Unified_CCX_Software_Compatibility_Matrix_for_10.6%281%29#Endpoint_Devices
As far as the way to daisy chain cisco voip phones is concerned, there must be two switch ports on the phone in order to achieve this. One port will be used to connect RJ-45 coming from the actual network switch and the other RJ-45 will be connected from the back of the phone (marked with PC) to the PC and thats it.
Settings like Span to PC Port, PC Port and PC Voice Vlan Access should be enabled at the phone level or enterprise level.
Regards
Deepak